I’m writing a novel where the same scene plays out from different characters’ perspectives. The dialogue is the same in multiple places in two chapters, but the thoughts expressed are different. I imagine this is overkill, but is there a way to associate two sentences in different documents within a project together, so that if I change one line, it changes it in both documents?
What I would do myself in your position is simply drop an inline annotation at the top of each section, with a link to the other matching section and a note that if you revise dialogue you should load up the other as well and make the edits there too. With split views this can be done pretty efficiently. It’s nothing fancy, but it gets the job done—and that’s a useful technique for all kinds of dependencies in a story, where future edits may impact other scenes. If you lay down the ground-work as you write, keeping things linked together like that, then it makes your job easier down the road.
As for what Scrivener can do, while there isn’t a tool that works in so specific a fashion as that, by its nature, there is a way of keeping text synced up between sections. If you take a look in §10.1.5, Including Text From Other Documents, in the user manual PDF, you’ll find a method for including whole sections into other sections. That’s the closest thing to what you’re trying to do, but the trick here is to think of how a “document” can be something very short, and potentially located outside of the draft entirely.
In some projects I will create a “Snippets” folder where I put short lines of text that are repeated frequently (and often these end up in footnotes, to illustrate the flexibility of how the feature can be used).
The downside is that the text itself doesn’t show up in the place where it will eventually be inserted, when you compile. All you see is the code, and for that reason I like to use the linking method described in the manual. Instead of specifying the name of the binder item to include, I just type in the <$include> placeholder and link it to that item. Then if I am unsure of the text, I can click it and read it.
So like I say, I don’t think that’s going to work for what you want, since it sounds like these two chapters would be mostly <$include> markers with a few different sentences here and there!